Fuse



Oct. 241, 1930. A. sTEuNMAYE-e FUSE 'original Filed March 7, 1927 Patented Oct. 21, 193@ UNITE/D STAT-ES PINT QFFIC'E ALVIIN G. STENMAY/ER, OF MILWAUKEE, WSCONSIN, ASSIGNOR, BY MESNIE ASSIGN- MENTS, TO LINE IYIATERAL COMPANY, OF IIIILVAUKEE, WSCO'NSL'N, lA CORPORA- TION OF DELAWARE Application led March 7, 1927, Serial No. 173,557.

1n my copending application, tiled July 12, 1926, Serial No. 121,925, l illustrate an iniproved fuse constructionA designed to insure the complete venting of the gases generated by the volatilization of the fuse element and to prevent the jumping of the current, which is of high voltage, from one terminal to the other and the consequent destruction of the entire fuse unit and its supporting contacts.

Vilhile the fuse illustrated in the copending application above referred to is eficient and practical, it has the objection that a set length of fuse element is necessitated, preventing the reloading of the fusefrom random lengths or by the use of the ordinary twisted fuse wire such as commonly carried by emergency men and this invention has as one of its objects the provision of an Vimproved fuse construction of the character described wherein random lengths of fuse element may be utilized, the excess length of the fuse being severed after the reloading operationY has been conipleted. A

Another objectionable feature of fuses of the. type especially designed for high voltage w rk is that if the fuse element has been destroyed, no indication exists as to the size of element requiredin replacement. Therefore, this invention has asanother object the provision of an improved fuse construction wherein the capacity ofthe elements is at all times visible`r which indication is on a visible portion ofthe element which remains after the element has blown. i

1t is a further object of this invention to provide an improved fuse construction of the character described having simplilied and e iicient means for renewably securing the fuse element in the holder.

And a still further object of this invention resides in the provision of an improved fuse holder which is so designed as to be capable of usewith maximum loads, which will eiliciently vent the gases generated by the volatilization of the fuse element upon its destruction by excessive overloads and which will effectively provide a barrier in the path of the gases to prevent the jumping of the current across the stationary contacts.

YVith the above and otherobjects in view Renewed Gotober 30, 1929.

which will appear as the description proceeds, my invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the herein disclosed invention may be made as come within the scope of the claims.

ln the accompanying drawing, I have illustrated one complete example ofthe physical embodiment of my invention constructed according to the best mode l have so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a view taken transversely through a fuse construction and its enclosing housing, parts thereof being in section and parts in elevation;

Figure 2 is an enlarged perspective view of the fuse holder removed from the'housing, parts thereof being in section and parts in elevation, said view being taken through Figure 1 on the plane of the line Q--Qg Figure 3 is a detail sectional view through the lower portion of the fuse proper, said view being taken through Figure 2 on the plane of the line 3 3, and

Figure l is a transverse sectional view taken through Figure 3 on the plane of the line Ll-AL Referring now more particularly to the accompanying drawing, in which l'ilre numerals designate like parts throughout ythe several views, the numeral 5 designates a boX or housing having apertures 6 in its rear wall 7 through which lead-in insulators 8 project. lThe lead-in insulators are secured in place by a mounting plate 9 as more fully and at length described in my cepending application hereinabove referred to, and have switch terminal members 10, of the clip type, mounted on their inner ends and connected with the service lines 11 which enter the housing through the insulators.

A fuse unit 12 including a fuse element 13 is removably secured in the terminal clips 1() to electrically bridge the same and the unit may be connected with the removable door 14 normally closing the front of the housing 5. The fuse unit consists of an elongated open ended tube 15 of suitable insulating material having a terminal engagthe upper end of the fuse element by folding the same upon itself in the manner invdicated by dotted'lines in Figure 1, between the upper end 22 of the element 16 and the top of the cap.' YThe fuse element 13 extends Vthroughout the length of the tube 15 and `is Vfolded upwardly Y.along the lower end thereof and clamped between the lowermost tapered end portion 23 of the element 17 and the Vinternal annular rib 24 of asleeve or vcollar member 25, the peripheral wall of the Y flange 24 being. taperedto conform with the Y of is exposed exteriorly of the unit.

tapered end portion 23 of the element 17.

@The 'collar 25 has its portion above the flange 24 internally threaded for detachable securement to an annular flange 26 formed on the element 17 e slightly above its tapered ,end portion 23 and the lower end portion ofV the fuse element extends upwardly through a slot or opening 27 in the collar 26 so that the eXtreme lower end portion 28 there- This construction permits the use of random lengths of fuse element asthe same may be readily clamped or secured in place and the excess off element cut offk leaving but the projecting portion 28 which is marked, as at 29, with the amperage'capacity offthe Velement, the illustration showing the elementY 13 as having a capacity of sixty amperes. The fuse element 13 likewise preferably has Yak portion 30 of reduced areaadjacent its upper end so thatdisruptioii thereof-upon excessiveV overload starts at.tlie upper end. This construction insures a good electrical connection between the fuse and the elements 16 and 17Vand permits an emergency man to use the twisted wire. of the typecommonly carried in an emergency kit for a teniporary replacement of the element las will be readily apparent.` As willi be apparent,

blowing ofthe fuse element leaves the extendedV end Vportionrwith its designator 29 unharmed so`A that the lineman Vwill vhavea ready sourcegof information as to the Vcapacity of elements required for replacement. A second tube 31 of greater diameter than the tube 15 and secured in the. sleeve 25 below the flange 24 is telescoped over that portion'ofthe tube 15 extended beyondl the ele'- ment 17 with its extreme lower end spaced slightly inwardly of the extreme lowerend of the tube 15. The portionof the fuse unit below the collar 25 extends exteriorly of the housing 5 through an opening 32 in the bottom wall thereof'so that the gases generated by the volatilization of the fuse element upon its being subjected to 'excessive over-V loads are quickly vented exteriorly of the housing to prevent the jumping of theA current across the contacts 10, the gases having a barrier in their'palth between the contacts formed by the lower end portion of theV tube 15 and the tube 31. The tube 31 terminating short ofthe adjacent end of the tube 15 permits the Vcomplete venting of the tube 15 with the least probability of leakage'of the current through the bore of the ftube 15 and upwardly through the spaces be-v tween the tube 31.

From the foregoing description taken in connection with the accompanying drawing,

,it will vbe Vreadily apparent to those skilled in the artv to which an invention of the char-Y acter described appertains that I provide an improved fuse construction which is very eficient in operation, will permit the ready rcnewal of the fuse element from random Vlengths of materiahwill permit of a visual v,unit and inspection of the fuse element proper, which will leave a record of `the element capacity after the same has'blown,

and which will have increased efficiency in service.

What I claim as my invention is: I 1, A fuse construction, comprising a pair of terminal engaging members, an insulating tube, means mounting one terminal engaging member on one end portion'of the tube,

Vmeans mounting the other terminal engaging member on the tube adjacent its other end, a fuse element having one end electrically connectedwith the first-mentioned member and passing through the tube and outwardly thereof with its other end extended along the outside of the tube to the other terminal engaging member, means electrically clamping the fuse element to said other terminal engaging member with its end exposed outwardly thereof, and a tube carried by said last-mentioned means and providing a cylin.

der substantially enclosing the portion of the fuse element extending along the outside of lli);

the first tube, said second tube terminating Y short of the adjacent end ofthe first tubev to insure complete venting ofthe first tube. i Y2. Afuse construction, comprising an in?Y sulating tube, a pair of terminal engaging members secured on the tube, a fuse element Y having one end electrically connected with one `member and passing outwardlythrough the tube and being directed alongthe exterior thereof to the other member, whereby the ele-v ment is of approximately hairpin shape, a threaded flange on the other member at a point spaced from the lower end thereof, an internally threaded sleeve adapted to be threaded on the lower end of the other member, means electrically clamping the lower end of the fuse eleme-nt against the side of the other member with its extreme end portion exposed, and a second tube of greater diameter than the first tube and carried by said sleeve and surrounding the projected end of the first tube.

3. A fuse construction, comprising an insulating tube, terminal engaging members mounted on the tube adjacent opposite ends thereof, a fuse element having its upper end electrically connected with the terminal engaging member adjacent the tube upper end and being passed through the tube lower end and up to the second of the terminal engaging members, said second terminal engaging member having an open ended recess in which the lower end portion of the fuse element is readily adjustable as to length, means securing the lower end portion of the fuse element in the recess and in electrical engagement with said second terminal engaging member, and a member having a bore of greater diameter than the lower end portion of the tube and into which tube the lower end portion and the portion of the fuse element extended therealong are inserted, the adjacent ends of said tube and member being open to the atmosphere.

4t. A fuse construction, comprising an insulating tube, a pair of terminal engaging members mounted on the tube adjacent opposite ends thereof, a fuse element having one end electrically connected with one terminal engaging member and having its other end portion passed through the tube outwardly of its other end and up to the second of the terminal ei gaginf.' n unbere, means electrically securing the fuse element to the second terminal engaging member with a portion thereof exposed, and means having an opening to provide a cylinder substantially receiving the portion of the tube and fuse element extending beyond the second terminal engaging member, said tube and last-inentioned means having their adjacent portions arranged to provide an air space therebetween and the adjacent ends of said tube and means being opened to the atmosphere.

5. A fuse construction, comprising an insulating tube, a pair of termina-l engaging members mounted on the tube adjacentopposite ends thereof, a fuse element having one end electrically connected with one terminal engaging member and being passed through the tube and its opposite end portion extended beyond the tube and passed along the outside thereof to the second of the terminal engaging members, means electrically connecting the fuse element with said second terminal engaging member with its end eX- posed inwardly thereof, said connecting means permitting longitudinal adjustment of the fuse element, and means having a bore to provide a cylinder substantially enclosing the portion of the fuse element extending along the outside of the tube, the outer end of said last means being spaced from the adjacent end of the tube to insure complete venting of the tube.

6. A fuse construction, comprising a pair of terminal engaging members, an insulating tube, means mounting al terminal enga-ging member at one end portion of the tube, means mounting another terminal engaging member on the tube adjacent its other e-nd, a fuse element having one end electrically connected with the first-mentioned member and passed through the tube outwardly of its other end and up to the other terminal engaging member, means electrically clamping the fuse element to the other terminal engaging member with the end portion thereof exposed, and a tube providing a cylinder substantially enclosing the lower portion of the first-mentioned tube and the portion of the fuse element extending along the side thereof.

7. A fuse construction, comprising a pair of terminal engaging members, an insulating tube, means mounting a terminal engaging member at one end portion of the tube, means mounting another terminal engaging member on the tube adjacent its other end, a fuse element having one end electrically connected with the first-mentioned member and passed tirough the tube outwardly of its other end and up to the other terminal engaging member, means electrically clamping the fuse element to the other terminal engaging member with the end portion thereof exposed, and a tube carried by said last-mentioned means providing a cylinder substantially enclosing the lower portion of the first-mentioned tube and the portion of the fuse element extending along the side thereof.

In testimony whereof I hereunto affix my signature.

ALW/VIN G. STEINMAYER. 

